arch/powerpc/platforms/iseries/irq.c

   1 /*
   2  * This module supports the iSeries PCI bus interrupt handling
   3  * Copyright (C) 20yy  <Robert L Holtorf> <IBM Corp>
   4  * Copyright (C) 2004-2005 IBM Corporation
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the:
  18  * Free Software Foundation, Inc.,
  19  * 59 Temple Place, Suite 330,
  20  * Boston, MA  02111-1307  USA
  21  *
  22  * Change Activity:
  23  *   Created, December 13, 2000 by Wayne Holm
  24  * End Change Activity
  25  */
  26 #include <linux/config.h>
  27 #include <linux/pci.h>
  28 #include <linux/init.h>
  29 #include <linux/threads.h>
  30 #include <linux/smp.h>
  31 #include <linux/param.h>
  32 #include <linux/string.h>
  33 #include <linux/bootmem.h>
  34 #include <linux/ide.h>
  35 #include <linux/irq.h>
  36 #include <linux/spinlock.h>
  37
  38 #include <asm/paca.h>
  39 #include <asm/iseries/hv_types.h>
  40 #include <asm/iseries/hv_lp_event.h>
  41 #include <asm/iseries/hv_call_xm.h>
  42 #include <asm/iseries/it_lp_queue.h>
  43
  44 #include "irq.h"
  45 #include "call_pci.h"
  46
  47 #if defined(CONFIG_SMP)
  48 extern void iSeries_smp_message_recv(struct pt_regs *);
  49 #endif
  50
  51 enum pci_event_type {
  52         pe_bus_created          = 0,    /* PHB has been created */
  53         pe_bus_error            = 1,    /* PHB has failed */
  54         pe_bus_failed           = 2,    /* Msg to Secondary, Primary failed bus */
  55         pe_node_failed          = 4,    /* Multi-adapter bridge has failed */
  56         pe_node_recovered       = 5,    /* Multi-adapter bridge has recovered */
  57         pe_bus_recovered        = 12,   /* PHB has been recovered */
  58         pe_unquiese_bus         = 18,   /* Secondary bus unqiescing */
  59         pe_bridge_error         = 21,   /* Bridge Error */
  60         pe_slot_interrupt       = 22    /* Slot interrupt */
  61 };
  62
  63 struct pci_event {
  64         struct HvLpEvent event;
  65         union {
  66                 u64 __align;            /* Align on an 8-byte boundary */
  67                 struct {
  68                         u32             fisr;
  69                         HvBusNumber     bus_number;
  70                         HvSubBusNumber  sub_bus_number;
  71                         HvAgentId       dev_id;
  72                 } slot;
  73                 struct {
  74                         HvBusNumber     bus_number;
  75                         HvSubBusNumber  sub_bus_number;
  76                 } bus;
  77                 struct {
  78                         HvBusNumber     bus_number;
  79                         HvSubBusNumber  sub_bus_number;
  80                         HvAgentId       dev_id;
  81                 } node;
  82         } data;
  83 };
  84
  85 static DEFINE_SPINLOCK(pending_irqs_lock);
  86 static int num_pending_irqs;
  87 static int pending_irqs[NR_IRQS];
  88
  89 static void int_received(struct pci_event *event, struct pt_regs *regs)
  90 {
  91         int irq;
  92
  93         switch (event->event.xSubtype) {
  94         case pe_slot_interrupt:
  95                 irq = event->event.xCorrelationToken;
  96                 if (irq < NR_IRQS) {
  97                         spin_lock(&pending_irqs_lock);
  98                         pending_irqs[irq]++;
  99                         num_pending_irqs++;
 100                         spin_unlock(&pending_irqs_lock);
 101                 } else {
 102                         printk(KERN_WARNING "int_received: bad irq number %d\n",
 103                                         irq);
 104                         HvCallPci_eoi(event->data.slot.bus_number,
 105                                         event->data.slot.sub_bus_number,
 106                                         event->data.slot.dev_id);
 107                 }
 108                 break;
 109                 /* Ignore error recovery events for now */
 110         case pe_bus_created:
 111                 printk(KERN_INFO "int_received: system bus %d created\n",
 112                         event->data.bus.bus_number);
 113                 break;
 114         case pe_bus_error:
 115         case pe_bus_failed:
 116                 printk(KERN_INFO "int_received: system bus %d failed\n",
 117                         event->data.bus.bus_number);
 118                 break;
 119         case pe_bus_recovered:
 120         case pe_unquiese_bus:
 121                 printk(KERN_INFO "int_received: system bus %d recovered\n",
 122                         event->data.bus.bus_number);
 123                 break;
 124         case pe_node_failed:
 125         case pe_bridge_error:
 126                 printk(KERN_INFO
 127                         "int_received: multi-adapter bridge %d/%d/%d failed\n",
 128                         event->data.node.bus_number,
 129                         event->data.node.sub_bus_number,
 130                         event->data.node.dev_id);
 131                 break;
 132         case pe_node_recovered:
 133                 printk(KERN_INFO
 134                         "int_received: multi-adapter bridge %d/%d/%d recovered\n",
 135                         event->data.node.bus_number,
 136                         event->data.node.sub_bus_number,
 137                         event->data.node.dev_id);
 138                 break;
 139         default:
 140                 printk(KERN_ERR
 141                         "int_received: unrecognized event subtype 0x%x\n",
 142                         event->event.xSubtype);
 143                 break;
 144         }
 145 }
 146
 147 static void pci_event_handler(struct HvLpEvent *event, struct pt_regs *regs)
 148 {
 149         if (event && (event->xType == HvLpEvent_Type_PciIo)) {
 150                 if (hvlpevent_is_int(event))
 151                         int_received((struct pci_event *)event, regs);
 152                 else
 153                         printk(KERN_ERR
 154                                 "pci_event_handler: unexpected ack received\n");
 155         } else if (event)
 156                 printk(KERN_ERR
 157                         "pci_event_handler: Unrecognized PCI event type 0x%x\n",
 158                         (int)event->xType);
 159         else
 160                 printk(KERN_ERR "pci_event_handler: NULL event received\n");
 161 }
 162
 163 /*
 164  * This is called by init_IRQ.  set in ppc_md.init_IRQ by iSeries_setup.c
 165  * It must be called before the bus walk.
 166  */
 167 void __init iSeries_init_IRQ(void)
 168 {
 169         /* Register PCI event handler and open an event path */
 170         int ret;
 171
 172         ret = HvLpEvent_registerHandler(HvLpEvent_Type_PciIo,
 173                         &pci_event_handler);
 174         if (ret == 0) {
 175                 ret = HvLpEvent_openPath(HvLpEvent_Type_PciIo, 0);
 176                 if (ret != 0)
 177                         printk(KERN_ERR "iseries_init_IRQ: open event path "
 178                                         "failed with rc 0x%x\n", ret);
 179         } else
 180                 printk(KERN_ERR "iseries_init_IRQ: register handler "
 181                                 "failed with rc 0x%x\n", ret);
 182 }
 183
 184 #define REAL_IRQ_TO_SUBBUS(irq) (((irq) >> 14) & 0xff)
 185 #define REAL_IRQ_TO_BUS(irq)    ((((irq) >> 6) & 0xff) + 1)
 186 #define REAL_IRQ_TO_IDSEL(irq)  ((((irq) >> 3) & 7) + 1)
 187 #define REAL_IRQ_TO_FUNC(irq)   ((irq) & 7)
 188
 189 /*
 190  * This will be called by device drivers (via enable_IRQ)
 191  * to enable INTA in the bridge interrupt status register.
 192  */
 193 static void iseries_enable_IRQ(unsigned int irq)
 194 {
 195         u32 bus, dev_id, function, mask;
 196         const u32 sub_bus = 0;
 197         unsigned int rirq = virt_irq_to_real_map[irq];
 198
 199         /* The IRQ has already been locked by the caller */
 200         bus = REAL_IRQ_TO_BUS(rirq);
 201         function = REAL_IRQ_TO_FUNC(rirq);
 202         dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
 203
 204         /* Unmask secondary INTA */
 205         mask = 0x80000000;
 206         HvCallPci_unmaskInterrupts(bus, sub_bus, dev_id, mask);
 207 }
 208
 209 /* This is called by iseries_activate_IRQs */
 210 static unsigned int iseries_startup_IRQ(unsigned int irq)
 211 {
 212         u32 bus, dev_id, function, mask;
 213         const u32 sub_bus = 0;
 214         unsigned int rirq = virt_irq_to_real_map[irq];
 215
 216         bus = REAL_IRQ_TO_BUS(rirq);
 217         function = REAL_IRQ_TO_FUNC(rirq);
 218         dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
 219
 220         /* Link the IRQ number to the bridge */
 221         HvCallXm_connectBusUnit(bus, sub_bus, dev_id, irq);
 222
 223         /* Unmask bridge interrupts in the FISR */
 224         mask = 0x01010000 << function;
 225         HvCallPci_unmaskFisr(bus, sub_bus, dev_id, mask);
 226         iseries_enable_IRQ(irq);
 227         return 0;
 228 }
 229
 230 /*
 231  * This is called out of iSeries_fixup to activate interrupt
 232  * generation for usable slots
 233  */
 234 void __init iSeries_activate_IRQs()
 235 {
 236         int irq;
 237         unsigned long flags;
 238
 239         for_each_irq (irq) {
 240                 irq_desc_t *desc = get_irq_desc(irq);
 241
 242                 if (desc && desc->handler && desc->handler->startup) {
 243                         spin_lock_irqsave(&desc->lock, flags);
 244                         desc->handler->startup(irq);
 245                         spin_unlock_irqrestore(&desc->lock, flags);
 246                 }
 247         }
 248 }
 249
 250 /*  this is not called anywhere currently */
 251 static void iseries_shutdown_IRQ(unsigned int irq)
 252 {
 253         u32 bus, dev_id, function, mask;
 254         const u32 sub_bus = 0;
 255         unsigned int rirq = virt_irq_to_real_map[irq];
 256
 257         /* irq should be locked by the caller */
 258         bus = REAL_IRQ_TO_BUS(rirq);
 259         function = REAL_IRQ_TO_FUNC(rirq);
 260         dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
 261
 262         /* Invalidate the IRQ number in the bridge */
 263         HvCallXm_connectBusUnit(bus, sub_bus, dev_id, 0);
 264
 265         /* Mask bridge interrupts in the FISR */
 266         mask = 0x01010000 << function;
 267         HvCallPci_maskFisr(bus, sub_bus, dev_id, mask);
 268 }
 269
 270 /*
 271  * This will be called by device drivers (via disable_IRQ)
 272  * to disable INTA in the bridge interrupt status register.
 273  */
 274 static void iseries_disable_IRQ(unsigned int irq)
 275 {
 276         u32 bus, dev_id, function, mask;
 277         const u32 sub_bus = 0;
 278         unsigned int rirq = virt_irq_to_real_map[irq];
 279
 280         /* The IRQ has already been locked by the caller */
 281         bus = REAL_IRQ_TO_BUS(rirq);
 282         function = REAL_IRQ_TO_FUNC(rirq);
 283         dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
 284
 285         /* Mask secondary INTA   */
 286         mask = 0x80000000;
 287         HvCallPci_maskInterrupts(bus, sub_bus, dev_id, mask);
 288 }
 289
 290 static void iseries_end_IRQ(unsigned int irq)
 291 {
 292         unsigned int rirq = virt_irq_to_real_map[irq];
 293
 294         HvCallPci_eoi(REAL_IRQ_TO_BUS(rirq), REAL_IRQ_TO_SUBBUS(rirq),
 295                 (REAL_IRQ_TO_IDSEL(rirq) << 4) + REAL_IRQ_TO_FUNC(rirq));
 296 }
 297
 298 static hw_irq_controller iSeries_IRQ_handler = {
 299         .typename = "iSeries irq controller",
 300         .startup = iseries_startup_IRQ,
 301         .shutdown = iseries_shutdown_IRQ,
 302         .enable = iseries_enable_IRQ,
 303         .disable = iseries_disable_IRQ,
 304         .end = iseries_end_IRQ
 305 };
 306
 307 /*
 308  * This is called out of iSeries_scan_slot to allocate an IRQ for an EADS slot
 309  * It calculates the irq value for the slot.
 310  * Note that sub_bus is always 0 (at the moment at least).
 311  */
 312 int __init iSeries_allocate_IRQ(HvBusNumber bus,
 313                 HvSubBusNumber sub_bus, HvAgentId dev_id)
 314 {
 315         int virtirq;
 316         unsigned int realirq;
 317         u8 idsel = (dev_id >> 4);
 318         u8 function = dev_id & 7;
 319
 320         realirq = (((((sub_bus << 8) + (bus - 1)) << 3) + (idsel - 1)) << 3)
 321                 + function;
 322         virtirq = virt_irq_create_mapping(realirq);
 323
 324         irq_desc[virtirq].handler = &iSeries_IRQ_handler;
 325         return virtirq;
 326 }
 327
 328 /*
 329  * Get the next pending IRQ.
 330  */
 331 int iSeries_get_irq(struct pt_regs *regs)
 332 {
 333         struct paca_struct *lpaca;
 334         /* -2 means ignore this interrupt */
 335         int irq = -2;
 336
 337         lpaca = get_paca();
 338 #ifdef CONFIG_SMP
 339         if (lpaca->lppaca.int_dword.fields.ipi_cnt) {
 340                 lpaca->lppaca.int_dword.fields.ipi_cnt = 0;
 341                 iSeries_smp_message_recv(regs);
 342         }
 343 #endif /* CONFIG_SMP */
 344         if (hvlpevent_is_pending())
 345                 process_hvlpevents(regs);
 346
 347         if (num_pending_irqs) {
 348                 spin_lock(&pending_irqs_lock);
 349                 for (irq = 0; irq < NR_IRQS; irq++) {
 350                         if (pending_irqs[irq]) {
 351                                 pending_irqs[irq]--;
 352                                 num_pending_irqs--;
 353                                 break;
 354                         }
 355                 }
 356                 spin_unlock(&pending_irqs_lock);
 357                 if (irq >= NR_IRQS)
 358                         irq = -2;
 359         }
 360
 361         return irq;
 362 }